A Convenient FeCl3-Mediated Synthesis of 5-Trifluoromethyl-1,2,4-triazoles from Trifluoroacetimidoyl Chlorides and Hydrazides

摘要

A low cost FeCl3-mediated cascade annulation of trifluoroacetimidoyl chlorides and hydrazides for the efficient synthesis of 5-trifluoromethyl-1,2,4-triazoles has been developed. The transformation proceeds through a cascade base-promoted intermolecular C-N bond formation and FeCl3-mediated intramolecular dehydration sequence under mild conditions. The protocol exhibits many notable features and can be readily scaled up to gram scale.